The present invention relates to novel pigment preparations having improved coloristic and rheological properties and to their preparation and use for pigmenting high molecular mass materials.
Pigment preparations are combinations of pigments with pigment dispersants that are structurally analogous to pigments and are substituted by groups having a specific activity. They are added to the pigments in order to facilitate dispersion in the application media, especially in varnishes, and to improve the rheological and coloristic properties of the pigments. The viscosity of the highly pigmented paint concentrates (millbase) is lowered and the flocculation of the pigment particles is lessened. By this means it is possible, for example, to increase the transparency and the gloss. This is a particular requirement in the case of metallic pigments.
A large number of proposals exist for improving the rheological and coloristic properties of organic pigments by adding pigment dispersants, although not always with the desired result. EP-A-0 321 919 describes the production of pigment preparations by mixing the base pigments with pigment derivatives that contain methyleneimidazolyl groups. In the field of perylene pigments, this results in pigment preparations whose coloristic properties no longer meet current requirements.
DE-A-3 106 906 describes the preparation of pigment dispersants that contain sulfonamide groups. The pigment dispersants described therein are based on perylene compounds but have considerable coloristic and rheological deficiencies.
DE-A-1 97 09 798 discloses pigment preparations comprising asymmetric, and U.S. Pat. No. 4 762 569 the production of pigment preparations based on symmetric, perylene-3,4,9,10-tetracarboxylic diimides. These pigment preparations are in many cases suitable only for use in solventborne systems. Also, they do not meet all of the requirements made of them in terms of rheological and coloristic properties. Especially at high levels of pigment dispersant, the coloristic properties are no longer adequate, and in many cases a distinct loss of gloss and a deviation in shade can be noted. Moreover, these pigment dispersants possess inadequate solvent fastness and fastness to overcoating, thus greatly restricting their universal application. Furthermore, in many varnish systems it is possible to observe instances of incompatibility with the binder.
EP-A-0 485 441 describes the production of pigment preparations based on acidic perylene-3,4,9,10-tetracarboxylic diimides. However, these pigment preparations do not meet all of the requirements made of them in terms of rheological and coloristic properties. When acidic perylene compounds are used in aqueous coating systems, which are often of alkaline pH, there may be problems, thus restricting their universal application.
A need for improvement existed and the object was therefore to provide pigment preparations which overcome the abovementioned disadvantages of the prior art in terms of coloristics, rheology, and universal applicability.
It has been found that the object is surprisingly achieved by pigment preparations which in addition to the base pigments comprise a combination of at least two specific perylene-3,4,9,10-tetracarboxylic diimides.
The invention provides pigment preparations comprising
a) at least one organic base pigment,
b1) at least one pigment dispersant of the formula (I), 
xe2x80x83in which the two radicals Z are identical or different and Z has the definition Z1, Z2, Z3 or Z4, with the proviso that both radicals Z are not simultaneously Z4, and in which
Z1 is a radical of formula (Ia),
xe2x80x94[Xxe2x80x94Y]qxe2x80x94[X1xe2x80x94Y1]rxe2x80x94[X2xe2x80x94NH]sHxe2x80x83xe2x80x83(Ia)
xe2x80x83in which
X, X1 and X2 are identical or different and are a branched or unbranched C2-C6-alkylene radical or a C5-C7-cycloalkylene radical which can be substituted by 1 to 4 C1-C4-alkyl radicals, hydroxyl radicals, hydroxyalkyl radicals having 1 to 4 carbon atoms, and/or by 1 or 2 further C5-C7-cycloalkyl radicals;
Y and Y1 are identical or different and are an NH, xe2x80x94O or N(C1-C6-alkyl) group, preferably xe2x80x94NCH3, or 
q is a number from 1 to 6, preferably 1, 2, 3 or 4;
r and s independently of one another are a number from 0 to 6, preferably 0, 1 or 2, r and s not simultaneously being zero; and in which
Z2 is a radical of formula (Ib),
xe2x80x94[Xxe2x80x94O]q1xe2x80x94[X1xe2x80x94O]qHxe2x80x83xe2x80x83(Ib)
xe2x80x83in which
q1 is a number from 0 to 6, preferably 0, 1, 2, 3 or 4;
and in which
Z3 is a radical of formula (Ic), 
xe2x80x83in which
R2 and R3 independently of one another are a hydrogen atom, a substituted or unsubstituted or partly fluorinated or perfluorinated alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted or partly fluorinated or perfluorinated alkenyl group having 2 to 20 carbon atoms, the substituents being able to be hydroxyl, phenyl, cyano, chloro, bromo, C2-C4-acyl or C1-C4-alkoxy and preferably from 1 to 4 in number, or
R2 and R3 together with the nitrogen atom, form a saturated, unsaturated or aromatic heterocyclic ring with or without a further nitrogen, oxygen or sulfur atom in the ring; and
X is as defined above;
Z4 is hydrogen, hydroxyl, amino, phenyl or C1-C20-alkyl, the phenyl ring and the alkyl group being able to be substituted by one or more, e.g. 1, 2, 3 or 4, substituents from the group consisting of Cl, Br, CN, OH, C6H5, carbamoyl, C2-C4-acyl and C1-C4-alkoxy, such as methoxy or ethoxy, and the phenyl ring also being able to be substituted by NR2R3, where R2 and R3 are as defined above, or the alkyl group is perfluorinated or partly fluorinated;
b2) at least one pigment dispersant of the formula (II), 
xe2x80x83in which
V is a bivalent radical xe2x80x94Oxe2x80x94,  greater than NR4, or  greater than Nxe2x80x94R5xe2x80x94Yxe2x88x92X+, and
W is the bivalent radical  greater than Nxe2x80x94R5xe2x80x94Yxe2x88x92X+,
D is a chlorine or bromine atom and, if o  greater than 1, may be a combination thereof, and
o is a number from 0 to 4;
R4 is a hydrogen atom or a C1-C20-alkyl group, especially C1-C4-alkyl, or is a phenyl group which can be unsubstituted or substituted one or more times, e.g., 1, 2 or 3 times, by halo such as chloro or bromo, C1-C4-alkyl such as methyl or ethyl, C1-C4-alkoxy such as methoxy or ethoxy, or phenylazo,
R5 is a C1-C18-alkylene group which can be interrupted one or more times within the Cxe2x80x94C-chain by a bridge member from the series consisting of xe2x80x94Oxe2x80x94, xe2x80x94NR6, xe2x80x94Sxe2x80x94phenylene, xe2x80x94COxe2x80x94, xe2x80x94SO2xe2x80x94, or xe2x80x94CR7R8 or a chemically logical combination thereof, in which R6, R7 and R8 independently of one another are each a hydrogen atom or a C1-C4-alkyl group which can be unsubstituted or substituted by a heterocyclic radical, preferably imidazole or piperazine,
but in particular is a straight-chain or branched C1-C6-alkylene group such as ethylene or propylene; or is a phenylene group which can be unsubstituted or substituted one or more times, e.g., 1, 2 or 3 times, by C1-C4-alkyl such as methyl or ethyl, or C1-C4-alkoxy such as methoxy or ethoxy,
Yxe2x88x92 is one of the anionic radicals xe2x80x94SO3xe2x88x92 or COOxe2x88x92, and
X+ is H+ or the equivalent 
xe2x80x83of a metal cation Mm+ from main groups 1 to 5 or from transition groups 1 or 2 or 4 to 8 of the Periodic Table of the Chemical Elements, m being one of the numbers 1, 2 and 3, and Mm+ defining, for example, Li1+, Na1+, K1+, Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Cu2+, Ni2+, Co2+, Zn2+, Fe2+, Al3+, Cr3+ or Fe3+;
or an ammonium ion N+R9R10R11R12, in which the substituents R9, R10, R11 and R12 independently of one another are each a hydrogen atom, C1-C30-alkyl, C1-C30-alkenyl, C5-C30-cycloalkyl, unsubstituted or C1-C8-alkyl-substituted phenyl, (C1-C4)-alkylene-phenyl, preferably benzyl, or are a (poly)alkyleneoxy group of the formula xe2x80x94[CH(R80)xe2x80x94CH2xe2x80x94O]kxe2x80x94H in which k is a number from 1 to 30 and R80 is hydrogen, C1-C4-alkyl or, if k greater than 1, is a combination thereof;
and in which alkyl, alkenyl, cycloalkyl, phenyl or alkylphenyl R9, R10, R11, and/or R12 can be further substituted by amino, hydroxyl, and/or carboxyl; or in which the substituents R9 and R10, together with the quaternary nitrogen atom, can form a five- to seven-membered saturated ring system comprising if desired further heteroatoms from the group consisting of O, S and N, an example of such a ring system being pyrrolidone, imidazolidine, hexamethyleneimine, piperidine, piperazine or morpholine;
or in which the substituents R9, R10, and R11, together with the quaternary nitrogen atom, can form a five- to seven-membered aromatic ring system comprising if desired further heteroatoms from the group consisting of O, S and N and onto which, if desired, additional rings are fused, an example of such a ring system being pyrrole, imidazole, pyridine, picoline, pyrazine, quinoline or isoquinoline; with the exception of a pigment preparation comprising
an organic base pigment, a pigment dispersant of the formula (IX) 
xe2x80x83and a pigment dispersant of the formula (X) 
Depending on the selection of the radicals Z, symmetric or asymmetric pigment dispersants of the formula (I) are obtained, asymmetric pigment dispersants of the formula (I) including those having different radicals Z1, Z2 and/or Z3.
Examples of pigment dispersants of interest are those of the formula (I), in which X, X1 and X2 are a C2-C4-alkylene radical or cyclohexylene.
Examples of pigment dispersants of particular interest are those of the formula (I), in which Z1 has one of the following definitions: xe2x80x94[(CH2)3xe2x80x94NH]2xe2x80x94H, xe2x80x94(CH2xe2x80x94CH2xe2x80x94NH)2H, 
xe2x80x94(CH2)3xe2x80x94NHxe2x80x94(CH2)2xe2x80x94NHxe2x80x94(CH2)3xe2x80x94NH2,
xe2x80x94(CH2)3xe2x80x94N(CH3)xe2x80x94(CH2)3xe2x80x94NH2, xe2x80x94(CH2)3xe2x80x94Oxe2x80x94(CH2)2xe2x80x94Oxe2x80x94(CH2)3xe2x80x94NH2,
xe2x80x94(CH2)3xe2x80x94Oxe2x80x94(CH2)3xe2x80x94Oxe2x80x94(CH2)3xe2x80x94NH2, xe2x80x94(CH2)2xe2x80x94NHxe2x80x94(CH2)3xe2x80x94NH2, xe2x80x94(CH2)3xe2x80x94NHxe2x80x94(CH2)2xe2x80x94NH2,
xe2x80x94(CH2xe2x80x94CH2xe2x80x94NH)3xe2x80x94H, xe2x80x94(CH2xe2x80x94CH2xe2x80x94NH)4xe2x80x94H, xe2x80x94(CH2xe2x80x94CH2xe2x80x94NH)5xe2x80x94H,
xe2x80x94(CH2)3xe2x80x94Oxe2x80x94(CH2)2xe2x80x94Oxe2x80x94(CH2)2xe2x80x94Oxe2x80x94(CH2)3xe2x80x94NH2, xe2x80x94(CH2)3xe2x80x94Oxe2x80x94(CH2)4xe2x80x94Oxe2x80x94(CH2)3xe2x80x94NH2, 
Examples of pigment dispersants of interest are those of the formula (I), in which Z2 has one of the definitions xe2x80x94(CH2)2xe2x80x94OH, xe2x80x94(CH2)3xe2x80x94OH, xe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94OH, xe2x80x94CH(CH2xe2x80x94CH3)CH2xe2x80x94OH, xe2x80x94CH(CH2OH)2, xe2x80x94(CH2)2xe2x80x94Oxe2x80x94(CH2)2xe2x80x94OH or xe2x80x94(CH2)3xe2x80x94Oxe2x80x94(CH2)2xe2x80x94Oxe2x80x94(CH2)2xe2x80x94OH.
Examples of pigment dispersants of interest are those of the formula (I) in which R2 and R3 independently of one another are a hydrogen atom, a C1-C6-alkyl group, a C1-C6-alkyl group substituted by 1 or 2 substituents from the group consisting of hydroxyl, acetyl, methoxy, ethoxy, chloro and bromo, or R2 and R3, together with the adjacent nitrogen atom, form an imidazolyl, piperidyl, morpholinyl, pipecolinyl, pyrrolyl, pyrrolidinyl, pyrazolyl or piperazinyl ring.
Examples of pigment dispersants of particular interest are those of the formula (I) in which Z3 has one of the definitions xe2x80x94(CH2)2xe2x80x94NH2, xe2x80x94(CH2)3xe2x80x94NH2, xe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94NH2, 
xe2x80x94(CH2)2xe2x80x94NHxe2x80x94CH3, xe2x80x94(CH2)2xe2x80x94N(CH3)2, xe2x80x94(CH2)2xe2x80x94NHxe2x80x94CH2xe2x80x94CH3, xe2x80x94(CH2)2xe2x80x94N(CH2xe2x80x94CH3)2, xe2x80x94(CH2)3xe2x80x94NHxe2x80x94CH3, xe2x80x94(CH2)3xe2x80x94N(CH3)2, xe2x80x94(CH2)3xe2x80x94NHxe2x80x94CH2xe2x80x94CH3 or xe2x80x94(CH2)3xe2x80x94N(CH2xe2x80x94CH3)2.
Examples of pigment dispersants of interest are those of the formula (I), in which Z4 is hydrogen, amino, phenyl, benzyl, NR2R3-substituted phenyl or benzyl, C1-C6-alkyl or C2-C6-alkyl substituted by 1 or 2 substituents from the group consisting of hydroxyl, acetyl, methoxy and ethoxy, with particular preference hydrogen, 
methyl, ethyl, propyl, butyl, benzyl, hydroxyethyl, hydroxypropyl or methoxypropyl.
The perylene compounds of the formulae (I) and (II) that are used in accordance with the invention as pigment dispersant b) can be prepared, for example, in accordance with DE-A-3 017 185 or EP-A-0 486 531 by reacting perylene-3,4,9,10-tetracarboxylic monoanhydride monoimides of the formula (IV) 
with one or more, preferably 1 or 2, amines of the formula (V)
H2Nxe2x80x94Zxe2x80x2xe2x80x83xe2x80x83(V)
in which Zxe2x80x2 in formula (IV) and Zxe2x80x2 in formula (V) can be identical or different and have the definition of Z or of R4 or R5xe2x80x94Yxe2x88x92X+,
or by reacting perylene-3,4,9,10-tetracarboxylic dianhydride of the formula (VI) 
with one or more, preferably 1 or 2, amines of the formula (V).
The reaction can be conducted in an aqueous, organic or aqueous-organic medium at temperatures, for example, of up to 250xc2x0 C., preferably up to 180xc2x0 C. Suitable organic media include inert organic solvents, preferably those whose boiling point is above that of water, examples being DMSO, chlorobenzene, dichlorobenzenes, trichlorobenzenes, relatively high-boiling alcohols, carboxamides, quinoline, imidazole, naphthalene, phenol and relatively high-boiling ethers. The amines of the formula (V) may also serve simultaneously as solvents. The pH of the aqueous or aqueous-organic medium can be acidic, neutral or alkaline, preferably between pH 3 and 14. It is also possible to use different amines at the same time in order to prepare mixtures of pigment dispersants of the formula (I) or of the formula (II).
The condensation is conducted with particular preference in aqueous solution under alkaline pH conditions at temperatures in the range between 50 and 180xc2x0 C. In the condensation it is judicious to use the amines in excess, judiciously in a molar excess up to 8 times, preferably up to 4 times. The products of the formula (I) formed are isolated from the reaction mixture preferably by filtration.
Examples of compounds which can be used as amines of the formula (V) are taurine (2-aminoethanesulfonic acid), xcex2-alanine, 4-aminobutyric acid, ammonia, methylamine, ethylamine, n-propylamine, n-butylamine, n-hexylamine, xcex2-hydroxyethylamine, xcex2- or xcex3-hydroxypropylamine, hydroxylamine, hydrazine, N,N-dimethyl-p-phenylenediamine, dimethylaminomethylamine, diethylaminoethylamine, 2-ethylhexylaminoethylamine, stearylaminoethylamine, oleylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, diethylaminobutylamine, dimethylaminoamylamine, diethylaminohexylamine, piperidinomethylamine, piperidinoethylamine, piperidinopropylamine, pipecolinoethylamine, pipecolinopropylamine, imidazolopropylamine, morpholinoethylamine, morpholinopropylamine, piperazinoethylamine, 2-(2-aminoethoxy)ethanol, 2-(2-(3-aminopropoxy)ethoxy)ethanol, 3,3xe2x80x2-oxybis(ethyleneloxy)bis(propylamine), ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2,2-dimethyl-1,3-propanediamine, isophoronediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, N,N-bis(3-aminopropyl)methylamine, tripropylenetetramine, (3-(2-aminoethyl)aminopropylamine, (N,Nxe2x80x2-bis-(3-aminopropyl)ethylenediamine), 4,7-dioxadecane-1,10-diamine, 4,9-dioxadodecane-1,12-diamine, 5-amino-1,3,3-trimethylcyclohexanemethaneamine or 1,4-bis(3-aminopropoxy)butane.
The term base pigment refers to organic pigments, or mixtures of organic pigments, which may also be in the form of conventional pigment preparations. Suitable base pigments for producing the pigment preparations of the invention are, for example, perylene, perinone, quinacridone, quinacridonequinone, anthraquinone, anthanthrone, benzimidazolone, disazo condensation, azo, indanthrone, phthalocyanine, triarylcarbonium, dioxazine, aminoanthraquinone, diketopyrrolopyrrole, thioindigo, isoindoline, isoindolinone, pyranthrone, isoviolanthrone and carbon black pigments or mixtures thereof. It is also possible to use more than one base pigment.
Examples of preferred base pigments for the purposes of the present invention are C.I. Pigment Red 123 (C.I. No. 71145), C.I. Pigment Red 149 (C.I. No. 71137), C.I. Pigment Red 178 (C.I. No. 71 155), C.I. Pigment Red 179 (C.I. No. 71 130), C.I. Pigment Red 190 (C.I. 71 140), C.I. Pigment Red 224 (C.I. No. 71 127), C.I. Pigment Violet 29 (C.I. No. 71 129), C.I. Pigment Orange 43 (C.I. No. 71 105), C.I. Pigment Red 194 (C.I. No. 71 100), C.I. Pigment Violet 19 (C.I. No. 73 900), C.I. Pigment Red 122 (C.I. No. 73 915), C.I. Pigment Red 192, C.I. Pigment Red 202 (C.I. No. 73 907), C.I. Pigment Red 207, C.I. Pigment Red 209 (C.I. No. 73 905), C.I. Pigment Red 206 (C.I. No. 73 900173 920), C.I. Pigment Orange 48 (C.I. No. 73 900/73 920), C.I. Pigment Orange 49 (C.I. No. 73 900/73 920), C.I. Pigment Orange 42, C.I. Pigment Yellow 147, C.I. Pigment Red 168 (C.I. No. 59 300), C.I. Pigment Yellow 120 (C.I. No. 11 783), C.I. Pigment Yellow 151 (C.I. No.13 980), C.I. Pigment Brown 25 (C.I. No. 12 510), C.I. Pigment Violet 32 (C.I. No. 12 517), C.I. Pigment Orange 64; C.I. Pigment Brown 23 (C.I. No. 20 060), C.I. Pigment Red 166 (C.I. No. 20 730), C.I. Pigment Red 170 (C.I. No.12 475), C.I. Pigment Orange 38 (C.I. No. 12 367), C.I. Pigment Red 188 (C.I. No. 12 467), C.I. Pigment Red 187 (C.I. No. 12 486), C.I. Pigment Orange 34 (C.I. No. 21 115), C.I. Pigment Orange 13 (C.I. No. 21 110), C.I. Pigment Red 9 (C.I. No. 12 460), C.I. Pigment Red 2 (C.I. No.12 310), C.I. Pigment Red 112 (C.I. No. 12 340), C.I. Pigment Red 7 (C.I. No. 12 420), C.I. Pigment Red 210 (C.I. No. 12 477), C. 1. Pigment Red 12 (C.I. No. 12 385), C.I. Pigment Blue 60 (C.I. No. 69 800), C.I. Pigment Green 7 (C.I. No. 74 260),C.I. Pigment Green 36 (C.I. No. 74 265); C.I. Pigment Blue 15:1,15:2, 15:3, 15:4, 15:6 and 15 (C.I. No. 74 160); C.I. Pigment Blue 56 (C.I. No. 42 800), C.I. Pigment Blue 61 (C.I. No. 42 765:1), C.I. Pigment Violet 23 (C.I. No. 51 319), C.I. Pigment Violet 37 (C.I. No. 51 345), C.I. Pigment Red 177 (C.I. No. 65 300), C.I. Pigment Red 254 (C.I. No. 56 110), C.I. Pigment Red 255 (C.I. No. 56 1050), C.I. Pigment Red 264, C.I. Pigment Red 270, C.I. Pigment Red 272 (C.I. No. 56 1150), C.I. Pigment Red 71, C.I. Pigment Orange 73, C.I. Pigment Red 88 (C.I. No. 73 312).
The amount of the pigment dispersants b1) of the formula (I) and of the pigment dispersants b2) of the formula (II) in the pigment preparations of the invention can vary within wide limits provided there is no adverse effect on the target pigment quality; nevertheless, the amount of a mixture of the pigment dispersants b1) and b2) is generally from 1 to 40% by weight, preferably from 2 to 30% by weight, based on the weight of the base pigment.
The quantitative ratios between the pigment dispersant of b1) and b2) can lie, for example, between 1:10 and 10:1 parts by weight, preferably between 1:5 and 5:1 parts by weight, in particular between 1:3 and 3:1 parts by weight.
In addition to the base pigment, the pigment dispersant b1) and the pigment dispersant b2), the pigment preparations of the invention may also comprise further customary additives, such as, for example, fillers, standardizers, surfactants, resins, defoamers, antidusting agents, extenders, shading colorants, preservatives, or drying retardants.
Preferred pigment preparations in the context of the present invention consist essentially of
a) from 40 to 99% by weight, preferably from 60 to 98% by weight, of at least one base pigment a),
b) from 1 to 40% by weight, preferably from 2 to 30% by weight, of a mixture of at least one, preferably 1, 2 or 3, pigment dispersants b1) of the formula (I) and at least one, preferably 1, 2 or 3, pigment dispersants b2) of the formula (II),
c) from 0 to 20% by weight, preferably from 0.1 to 15% by weight, of surfactants, and
d) from 0 to 20% by weight, preferably from 0.1 to 10% by weight, of other customary additives, the proportions of the respective components being based on the total weight of the preparation (100% by weight).
Suitable surfactants include customary anionic, cationic or nonionic surfactants or mixtures thereof, examples of anionic substances being fatty acid taurides, fatty acid N-methyltaurides, fatty acid isethionates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenol polyglycol ether sulfates and fatty alcohol polyglycol ether sulfates; fatty acids, e.g., palmitic, stearic and oleic acid; soaps, e.g., alkali metal salts of fatty acids, naphthenic acids and resin acids, such as abietic acid, alkali-soluble resins, e.g., rosin-modified maleate resins and condensation products based on cyanuric chloride, taurine, N,N-dialkylaminoalkylamine, such as N,N-diethylaminopropylamine, and p-phenylenediamine; preference is given to resin soaps, i.e., alkali metal salts of resin acids. Examples of suitable cationic substances are quaternary ammonium salts, fatty amine ethoxylates, fatty amine polyglycol ethers, and fatty amines. Examples of suitable nonionic substances are amine oxides, fatty alcohol polyglycol ethers, fatty acid polyglycol esters, and alkylphenol polyglycol ethers.
The pigment preparations of the invention are generally solid systems of free-flowing pulverulent consistency, or granules.
The dispersing effect which can be achieved in accordance with the invention is assumed to derive from a modification of the surface structure of the base pigments by the pigment dispersants of b1) and b2). Thus in a range of cases the efficacy of the pigment dispersants of b1) and b2), and the quality of the pigment preparations produced therewith, are dependent on the point in time at which the pigment dispersants of b1) and b2) are added in the production process of the base pigment. The pigment dispersants of b1) and b2) can be added simultaneously or at different points in time or can be mixed prior to their addition.
The efficacy of the pigment dispersants of b1) and b2) may also depend on their particle size and particle morphology and on the extent of the available pigment surface. It may be advantageous to add the pigment dispersants of b1) and b2) to the base pigment only in the prospective application medium. The optimum concentration of the pigment dispersants of b1) and b2) in each case must be determined by means of preliminary guideline experiments, since the enhancement of the properties of the base pigments is not always in linear proportion to the amount of pigment dispersant.
The pigment preparations of the invention can be mixtures of one or more, preferably 1 or 2, base pigments with one or more, preferably 1 or 2, of the pigment dispersants of b1) and with or more, preferably 1 or 2, of the pigment dispersants of b2). The invention also provides a process for producing a pigment preparation of the invention, which comprises mixing the pigment dispersant(s) of b1), the pigment dispersant(s) of b2), and the base pigment(s) with one another or allowing them to act on one another at any desired point in time during their production process.
The production process of an organic pigment embraces its synthesis, possible fine division, by grinding or reprecipitation, for example, possibly a finish, and its isolation as a presscake or in the form of dry granules or powder. For example, the pigment dispersants of b1) and b2) can be added prior to or during the pigment synthesis, immediately prior to or during a fine division process or a subsequent finish. The temperatures prevailing in the course of these processes can be, for example, from 0 to 200xc2x0 C. The pigment dispersants of b1) and b2) can of course also be added in portions at different times.
The addition of the pigment dispersants of b1) and b2) in the content of a fine division process takes place, for example, prior to or during the dry grinding of a crude pigment with or without additional grinding auxiliaries on a roll mill or vibratory mill, or prior to or during the wet grinding of a crude pigment in an aqueous, aqueous-organic or organic grinding medium in, for example, a bead mill. It is has also proven suitable to add the pigment dispersants of b1) and b2) before or after finishing the base pigment in an aqueous, aqueous-alkaline, aqueous-organic, or organic medium.
The pigment dispersants of b1) and b2) can also be added to the water-moist pigment presscake before drying and incorporated, in which case the pigment dispersants of b1) and b2) may themselves likewise be present as presscakes. A further possibility is to make dry mixes of powders or granules of the pigment dispersants of b1) and b2) with the powder or granules of one or more base pigments.
It is possible, furthermore, to synthesize one or more pigment dispersants of b1) and b2) and a perylene pigment as a mixture by reacting compounds of the formula (IV) and/or (VI) with an amine of the formula (VII)
H2Nxe2x80x94Z4xe2x80x83xe2x80x83(VII)
so that the pigment preparation is obtained directly.
The pigment preparations obtainable in accordance with the present invention are notable for their outstanding coloristic and rheological properties, especially for outstanding rheology, high flocculation stability, high transparency, ready dispersibility, excellent gloss behavior, high color strength, excellent fastness to overcoating and solvents, and very good weather fastness. They are suitable for use in both solventborne and aqueous systems.
The pigment preparations produced in accordance with the invention can be used to pigment high molecular mass organic materials of natural or synthetic origin, examples being plastics, resins, varnishes, paints, electrophotographic toners and developers, and writing, drawing and printing inks.
Examples of high molecular mass organic materials which can be pigmented with said pigment preparations are cellulose ethers and cellulose esters, such as ethylcellulose, nitrocellulose, cellulose acetate or cellulose butyrate, natural resins or synthetic resins, such as addition-polymerization resins or condensation resins, e.g., amino resins, especially urea-formaldehyde and melamine-formaldehyde resins, alkyd resins, acrylic resins, phenolic resins, polycarbonates, polyolefins, such as polystyrene, polyvinyl chloride, polyethylene, polypropylene, polyacrylonitrile, polyacrylates, polyamides, polyurethanes or polyesters, rubber, casein, silicone, and silicone resins, individually or in mixtures.
In this context it is unimportant whether the abovementioned high molecular mass organic compounds are present in the form of plastic masses, melts, spinning solutions, varnishes, paints or printing inks. Depending on the intended use it is found advantageous to utilize the pigment preparations obtained in accordance with the invention as a blend or in the form of prepared formulations or dispersions. Based on the high molecular mass organic material to be pigmented, the pigment preparations of the invention are used in an amount of preferably from 0.05 to 30% by weight, more preferably from 0.1 to 10% by weight.
The pigment preparations of the invention are also suitable as colorants in electrophotographic toners and developers, such as one- or two-component powder toners (also called one- or two-component developers), magnetic toners, liquid toners, polymerization toners, and specialty toners (L. B. Schein, xe2x80x9cElectrophotography and Development Physicsxe2x80x9d; Springer Series in Electrophysics 14, Springer Verlag, 2nd edition, 1992).
Typical toner binders are addition polymerization, polyaddition and polycondensation resins, such as styrene, styrene-acrylate, styrene-butadiene, acrylate, polyester, phenol-epoxy resins, polysulfones, polyurethanes, individually or in combination, and also polyethylene and polypropylene, which may include further constituents, such as charge control agents, waxes or flow assistants, or may be modified subsequently with these additives.
Furthermore, the pigment preparations of the invention are suitable as colorants in powders and powder coating materials, especially in triboelectrically or electrokinetically sprayable powder coating materials, which are used to coat the surfaces of articles made, for example, of metal, wood, plastic, glass, ceramic, concrete, textile material, paper or rubber (J. F. Hughes, xe2x80x9cElectrostatics Powder Coatingxe2x80x9d Research Studies, John Wiley and Sons, 1984).
Typical powder coating resins employed are epoxy resins, carboxyl- and hydroxyl-containing polyester resins, polyurethane resins and acrylic resins, together with customary hardeners. Resin combinations are also used. For example, epoxy resins are frequently used in combination with carboxyl- and hydroxy-containing polyester resins. Typical hardener components (depending on the resin system) are, for example, acid anhydrides, imidazoles, and also dicyandiamide and its derivatives, blocked isocyanates, bisacylurethanes, phenolic resins and melamine resins, triglycidyl isocyanurates, oxazolines, and dicarboxylic acids.
In addition, the pigment preparations of the invention are suitable for use as colorants in ink jet inks on either an aqueous or nonaqueous basis and in those inks which operate in accordance with the hot-melt technique.
In addition, the pigment preparations of the invention are also suitable as colorants for color filters and for both additive and subtractive color generation. It is also possible for the pigment dispersants of b1) and b2) to be added to the base pigment, or vice versa, only in the application medium. The invention therefore also provides a prepared pigment formulation consisting essentially of said base pigment, said pigment dispersants of b1) and b2), said high molecular mass organic material, especially varnish, if desired, surfactants and/or further customary additives. The overall amount of base pigment plus pigment dispersants of b1) and b2) is from 0.05 to 30% by weight, preferably from 0.1 to 10% by weight, based on the overall weight of the prepared pigment formulation.
In order to evaluate the properties in the coatings sector of the pigment preparations produced in accordance with the invention, a selection was made from among the large number of known varnishes of an alkyd-melamine resin varnish (AM) containing aromatic components and based on a medium-oil alkyd resin and on a butanol-etherified melamine resin, of a polyester varnish (PE) based on cellulose acetobutyrate and a melamine resin, of a high-solids acrylic resin stoving varnish based on a nonaqueous dispersion (HS), and of a polyurethane-based aqueous varnish (PU).
The color strength and shade were determined in accordance with DIN 55986. The rheology of the millbase after dispersion (millbase rheology) was evaluated visually on the basis of the following five-point scale:
Following dilution of the millbase to the final pigment concentration, the viscosity was evaluated using the Rossmann viscospatula, type 301, from Erichsen.
Gloss measurements were carried out on cast films at an angle of 20xc2x0 in accordance with DIN 67530 (ASTM D 523) using the xe2x80x9cmultiglossxe2x80x9d gloss meter from Byk-Mllinckrodt. The solvent fastness was determined in accordance with DIN 55976. The fastness to overcoating was determined in accordance with DIN 53221.